And BTW, why would the bank "reject" credits after holding them for a few days?
Imagine you are outside the US. Gox, of course, is also outside the US. You wire USD to Gox. Your bank sends a message to Gox's bank instructing them to credit Gox's account, which they do. In parallel with this, they send instructions to arrange a covering payment between the US banks that your bank and Gox's bank use to settle USD payments (so called 'correspondent banks')
One or other of the correspondent banks' compliance departments then decides to refuse the covering payment for some reason. So Gox's bank finds itself out of pocket, because it has not been paid the funds for the transfer. So obviously Gox's bank reverses the transfer.
We've had at least one report of a withdrawal wire being reversed a couple of weeks after the fact (apparently as a result of Citibank's compliance department blocking a covering payment) so it's not at all surprising that similar has happened with deposit wires.
roy
Was that for an international wire transfer through the SWIFT system? Details would be useful.
SWIFT rules don't allow banks to revoke transactions for SwiftPay transactions up to USD 20,000 (50,000 EUR between banks in the EU). Settlement has to occur within six days. "Priority" transactions are even less revocable. Banks have to sign a service level agreement with SWIFT to use the system. Once the bank has sent payment instructions via SWIFT, the bank is obligated to cover them with bank funds. It's not at the option of the sending bank.
ACH is different. That's more of a consumer-level system, with more "undo" features.
Law Enforcement Agency 
